the drag bars seem to be very fussy about that kinda thing.
Your telling me! I had to unscrew one side of my tach so the master cylinder would fit. Now it's crooked! Oh well, one thing at a time.
How did you shorten the cables?
Cut them and re-soldered the ends. You have to be very confident in your soldering though, because a bad joint there will cause some tense moments on the road! Carb cables are no probs, but the clutch has some pretty heavy pressure on it. The clutch cable iis much longer so you can usually find some way to route it without resorting to cutting. I even found that strapping the clutch cable to the frame caused too much drag. Cables, especially worn ones, are very particular about any bends, even minor ones, and if they have worn in one position, hate to be moved.
I actually reversed the angled fitting at the master cylinder to make the hose fit. A real pain it the ass to fit all the stuff on the bars for sure. I found drag bars uncomfortable and ended up going with clubmans after one season anyway, and will likely try clipons next.